In the alumino-thermite process,what does $Al$ act as?

In which of the following pairs of metals are both commercially extracted from their respective ores by the carbon reduction method?

Which flux is used to remove $SiO_2$ impurity?

The Ellingham diagram is a plot between:

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: In the Ellingham diagram,a sharp change in slope of the line is observed for $Mg \rightarrow MgO$ at $\sim 1120^{\circ} C$.
Reason $R$: There is a large change of entropy associated with the change of state.
In the light of the above statements,choose the correct answer from the options given below.

The flux used to remove the $FeO$ impurity present in the mixture obtained from the roasting of copper pyrites,and its nature,is .....